In general, before using a blood purification circuit for dialysis, there is performed a treatment of eliminating foreign substances and air existing in the blood circuit by introducing a priming liquid (generally, physiological saline is used) to fill a blood circuit therewith, that is, a priming treatment.
In a conventional dialysis apparatus, physiological saline is used to manually conduct priming of the blood circuit. However, recently, the priming is conducted by using an automatic priming apparatus.
As the automatic priming apparatus, Patent Document 1 discloses the following: that is, an artificial dialysis apparatus including a blood circuit having a dialyzer, which is provided with a blood pump, in which an arterial blood circuit and a venous blood circuit are connected to each other to form a circulation circuit, an overflow tube and an opening and closing means are provided above a drip chamber of the blood circuit, and the blood pump is actuated in a state where the opening and closing means of the tube is opened to allow a priming liquid to circulate through the circuit and the priming liquid is supplied from a priming liquid storage container to the circulation circuit at a predetermined flow rate, thereby discharging a part of the priming liquid from the overflow tube and conducting the priming.
However, in a case where the priming is conducted by this method, air remains in an inlet-side drip chamber. Therefore, there arises a problem in that the drip chamber cannot be filled with the priming liquid (physiological saline).
In order to solve the problem, Patent Document 2 suggests an automatic priming method for a blood purification circuit, in which an arterial-side chamber (corresponding to the inlet-side drip chamber of Patent Document 1 described above) provided in a blood circuit is installed while being directed upside down and priming is conducted. In a case where the method is adopted, at a time of a dialysis treatment performed afterwards, there is required an operation of returning the installation direction to an original direction. Without this operation, it is impossible to perform trapping of bubbles, which is one object of the drip chamber.
Patent Document 1: Japanese Utility Model Examined Publication No. Hei 05-19076
Patent Document 2: Japanese Patent Application Laid-open No. Hei 08-38597